+@c Copyright (C) 2011-2016 Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
@chapter Z80 Dependent Features
@end ifset
-@c DO-NOT-COMMIT
@ifclear GENERIC
@node Machine Dependencies
@item -r800
Produce code for the R800 processor. The assembler does not support
undocumented instructions for the R800.
-In line with common practice, @code{@value{AS}} uses Z80 instriction names
+In line with common practice, @code{@value{AS}} uses Z80 instruction names
for the R800 processor, as far as they exist.
@end table
The assembler syntax closely follows the 'Z80 family CPU User Manual' by
Zilog.
In expressions a single @samp{=} may be used as ``is equal to''
-comparison operator.
+comparison operator.
Suffices can be used to indicate the radix of integer constants;
@samp{H} or @samp{h} for hexadecimal, @samp{D} or @samp{d} for decimal,
@samp{Q}, @samp{O}, @samp{q} or @samp{o} for octal, and @samp{B} for
binary.
-The suffix @samp{b} denotes a backreference to local label.
+The suffix @samp{b} denotes a backreference to local label.
@menu
* Z80-Chars:: Special Characters
@cindex line comment character, Z80
@cindex Z80 line comment character
-The semicolon @samp{;} is the line comment character;
+The semicolon @samp{;} is the line comment character;
+
+If a @samp{#} appears as the first character of a line then the whole
+line is treated as a comment, but in this case the line could also be
+a logical line number directive (@pxref{Comments}) or a preprocessor
+control command (@pxref{Preprocessing}).
+
+@cindex line separator, Z80
+@cindex statement separator, Z80
+@cindex Z80 line separator
+The Z80 assembler does not support a line separator character.
@cindex location counter, Z80
@cindex hexadecimal prefix, Z80
@cindex character escapes, Z80
@cindex Z80, \
A backslash @samp{\} is an ordinary character for the Z80 assembler.
-
+
@cindex character constant, Z80
@cindex single quote, Z80
@cindex Z80 '
The single quote @samp{'} must be followed by a closing quote. If there
-is one character inbetween, it is a character constant, otherwise it is
+is one character in between, it is a character constant, otherwise it is
a string constant.
@node Z80-Regs
@cindex register names, Z80
The registers are referred to with the letters assigned to them by
-Zilog. In addition @command{@value{AS}} recognises @samp{ixl} and
+Zilog. In addition @command{@value{AS}} recognizes @samp{ixl} and
@samp{ixh} as the least and most significant octet in @samp{ix}, and
-similarly @samp{iyl} and @samp{iyh} as parts of @samp{iy}.
+similarly @samp{iyl} and @samp{iyh} as parts of @samp{iy}.
@c The @samp{'} in @samp{ex af,af'} may be omitted.
@cindex case sensitivity, Z80
Upper and lower case are equivalent in register names, opcodes,
-condition codes and assembler directives.
+condition codes and assembler directives.
The case of letters is significant in labels and symbol names. The case
is also important to distinguish the suffix @samp{b} for a backward reference
to a local label from the suffix @samp{B} for a number in binary notation.
@section Z80 Assembler Directives
@command{@value{AS}} for the Z80 supports some additional directives for
-compatibility with other assemblers.
+compatibility with other assemblers.
@cindex Z80-only directives
These are the additional directives in @code{@value{AS}} for the Z80:
@item db @var{expression}|@var{string}[,@var{expression}|@var{string}...]
@itemx defb @var{expression}|@var{string}[,@var{expression}|@var{string}...]
For each @var{string} the characters are copied to the object file, for
-each other @var{expression} the value is stored in one byte, ignoring
-overflow.
+each other @var{expression} the value is stored in one byte.
+A warning is issued in case of an overflow.
@item dw @var{expression}[,@var{expression}...]
@itemx defw @var{expression}[,@var{expression}...]
For each @var{expression} the value is stored in two bytes, ignoring
-overflow.
+overflow.
+
+@item d24 @var{expression}[,@var{expression}...]
+@itemx def24 @var{expression}[,@var{expression}...]
+For each @var{expression} the value is stored in three bytes, ignoring
+overflow.
+
+@item d32 @var{expression}[,@var{expression}...]
+@itemx def32 @var{expression}[,@var{expression}...]
+For each @var{expression} the value is stored in four bytes, ignoring
+overflow.
@item ds @var{count}[, @var{value}]
@itemx defs @var{count}[, @var{value}]
-@c Synonyms for @code{ds.b},
-@c which should have been described elsewhre
+@c Synonyms for @code{ds.b},
+@c which should have been described elsewhere
Fill @var{count} bytes in the object file with @var{value}, if
@var{value} is omitted it defaults to zero.
@item @var{symbol} equ @var{expression}
@itemx @var{symbol} defl @var{expression}
-These directives set the value of @var{symbol} to @var{expression}. To
-keep code portable to other assemblers it is best to use @samp{equ} for
-the first definition and @samp{defl} for redefinitions.
+These directives set the value of @var{symbol} to @var{expression}. If
+@code{equ} is used, it is an error if @var{symbol} is already defined.
+Symbols defined with @code{equ} are not protected from redefinition.
@item set
-This is a normal instruction on Z80, and not an assembler directive.
+This is a normal instruction on Z80, and not an assembler directive.
@item psect @var{name}
-A synonym for @xref{Section}, no second argument should be given.
+A synonym for @xref{Section}, no second argument should be given.
@ignore
-The following attributes will possibly be recognised in the future
+The following attributes will possibly be recognized in the future
@table @code
@item abs
The section is to be absolute. @code{@value{AS}} will issue an error
@node Z80 Opcodes
@section Opcodes
-In line with commmon practice Z80 mnonics are used for both the Z80 and
-the R800.
+In line with common practice, Z80 mnemonics are used for both the Z80 and
+the R800.
In many instructions it is possible to use one of the half index
registers (@samp{ixl},@samp{ixh},@samp{iyl},@samp{iyh}) in stead of an
synonym for @samp{sli}.
@item @var{op} (ix+@var{d}), @var{r}
-This is equivalent to
+This is equivalent to
@example
ld @var{r}, (ix+@var{d})
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